1. Field of the Invention
The invention relates to push-pull type closures which make it possible to drink directly from a neck of a bottle.
2. Description of the Related Art
Such closures are conventionally composed of a base, a valve lifter and a protective cap, as is seen, for example, in U.S. Pat. No. 5,813,575.
The cap and/or the valve lifter may be provided with tell-tales or tamper indicating components for showing tampering. Such tamper indicating components complicate the manufacturing of molds, molding and assembly of the three parts.
The invention has for its object to provide a closure system of the type set forth hereinabove comprising a perfect sealing means before opening and forming a tamper indicator upon first opening.
To this end, the invention relates to a push-pull closure which includes a base provided with an internal thread, a valve lifter associated with the base and movable relatively to the base between a closing position and an opening position, and a cap covering the valve lifter before the closure is opened for a first time, and wherein the closure comprises a tamperproof inner seal welded or adhered on a top part of the valve lifter.
An outer lateral skirt of the base is extended along its lower part by a tamperproof band connected by frangible lugs to a lower edge of the skirt.
The frangible bridges or lugs are separated from one another by zones of abutment abutting against the lower edge of the outer lateral skirt when the closure is positioned on a neck of a recipient or container.
The valve lifter comprises a convex top extended, in its lower part, by an annular wall of which the shape of the inner surface corresponds substantially to an outer surface of an upper part of the base. The wall of the valve lifter comprises an inner shoulder abutting, when the valve lifter is in a closed position, against a surface of a shoulder of the base. The inner surface of the wall is, in its upper part, in contact with a bead defining an end zone of the base. Clips inside a cap are in register with the bottom wall of the valve lifter so as to secure the cap upon reclosure.